Problem: Ishaan is 3 times as old as Daniel and is also 10 years older than Daniel. How old is Daniel?
Explanation: We can use the given information to write down two equations that describe the ages of Ishaan and Daniel. Let Ishaan's current age be $i$ and Daniel's current age be $d$ $i = 3d$ $i = d + 10$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $d$ , and both of our equations have $i$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $3d$ $-$ $ (d + 10)$ which combines the information about $d$ from both of our original equations. Solving for $d$ , we get: $2 d = 10$ $d = 5$.